This sign may date from as early as the 1920s, and was hanging at the CTA's Madison & Wabash Loop elevated station until the CTA removed it from service and donated it to NMAH for the America on the Move exhibition.

Chicago's four early rapid transit "L" lines were privately owned and operated, each serving a different area of the rapidly growing city . The first line opened in 1892, the last in 1900. In 1897, Chicago's Union Loop elevated tracks were put into operation, allowing all the rapid transit lines to bring passengers into the city's central business district. The entire system was municipilized in 1947, when the newly formed Chicago Transit Authority took control of most of the city's rail and street transit operations.